The number “911” is a universal emergency number for the entire United States. According to the National Emergency Number Association (NENA), in year 2000, approximately 150 million calls were made to the 911 emergency number. People born in the 1960s or later have grown up with 911 and have had enough exposure to the 911 emergency system that it has become second nature to them.
A standard emergency number such as 911 did not exist prior to 1968. The number 911, however, was not selected arbitrarily. Rather, it was selected because it is unique, short, and easy to remember. More importantly, the number 911 had never been designated for an office code, area code or service code so it was available for use as an exclusive, universal, emergency number. Once the number 911 was selected, a department was set up by the then Bell System to develop the infrastructure to support the 911 emergency number system.
Today in North America the number 911 is the universally dedicated emergency number for both wireline and wireless systems. Dialing 911 connects the caller with a Public Safety Answering Point (PSAP) attendant who then dispatches the appropriate emergency service depending on the nature of the emergency to the place where the call was placed. Emergency services include ambulance, police, fire, and/or rescue teams.
The first generation 911 emergency system was not, however, without problems. One being that the PSAP position attendant dealing with nearly hysterical people would sometimes be unable to receive all the information necessary for dispatching the appropriate emergency service. A piece of vital information that was often omitted by the caller was the location information. If the caller hung up before providing the location information, the PSAP attendant had no way of knowing who called and from where the call was made. Furthermore, without knowledge of the originating number there was the potential for a significant level of false emergencies.